Click Here for the full article.

Measure the total time of entry and verify the time between keystrokes to help authenticate a user regardless of the data being entered. Require nonprintable characters, such as backspace and break, in the password to enable new levels of password obfuscation. Learn how to apply the open source tools xev and Perl in keystroke dynamics to measure the more-subtle characteristics of human-computer interaction.

Original link at IBM developerworks. Please use the cached copy if the link is dead.
Date